Menopausal symptoms (e.g., vasomotor symptoms, loss of libido, sleep disturbances and nausea) are experienced by many pre-, peri- and post-menopausal women. Vasomotor symptoms (e.g., hot flashes and night sweats) are believed to arise due to decreases in estrogen production most commonly associated with natural or surgically induced menopause.
Hot flashes are sudden, intense, hot feelings on the face and upper body and are accompanied by differing degrees of flushing, palpitations, anxiety, irritability, sleep disturbances, and sweating. While the cause of hot flashes associated with vasomotor symptoms has not yet been fully elucidated, it has been hypothesized that hot flashes result from the brain's response to diminished hormones or hormonal fluctuations associated with the menopausal transition. (See e.g. Utian, Health and Quality of Life Outcomes, 2005, 3:47.)
Hot flashes affect each woman differently and typically last for a few minutes but can last for up to ten minutes or more in severe cases. Symptoms associated with hot flashes can range from mild to severe, with severe symptoms significantly interfering with a woman's daily life. Vasomotor symptoms can also arise as a result of treatments, such as treatment for breast cancer, that utilize antiestrogen therapy, result in chemo-therapy induced menopause, or that utilize compounds that modulate the estrogen receptor. While vasomotor symptoms mainly affect women, men can also suffer from vasomotor symptoms. For example, men undergoing treatment for prostate cancer and benign prostatic hyperplasia (BPH) can experience hot flashes.
Hot flashes are associated with natural, surgical, transient and iatrogenic menopause also a common symptom for women undergoing treatment for breast cancer. (See e.g. Pandya, Lancet, 2005, 366: 818-24.)
Vasomotor symptoms (e.g., hot flashes and night sweats) have traditionally been treated using hormone replacement therapy (HRT). However, the discovery that HRT can cause significant side effects has resulted in a reluctance to utilize HRT for treatment of conditions related to decreases in estrogen production. These side effects, including an increased risk of cardiovascular disease and uterine or breast cancer, are thought to be the result of undesirable estrogen activity in the relevant tissue.
None of the treatments for vasomotor symptoms, including hot flashes, have been completely effective. Thus there exists a need for more effective treatments, including treatment, of vasomotor symptoms such as hot flashes and night sweats, without the sides effects associated with hormone replacement therapy.